Seeking a Stimulating Solution for Alzheimer's

This past November, Johns Hopkins surgeons eased a fine electrode into the brain of a patient in early-stage Alzheimer’s disease, down to the fornix, a site hard-hit by the illness.

Far from being routine therapy, the operation was the first in this country to explore deep brain stimulation (DBS) for Alzheimer’s. Its outcome shores up work to see if the technique might stop or slow patients’ decline into dementia.

This new trial follows a preliminary study in Toronto, Canada, in which surgeons implanted the stimulating devices in six AD patients. Researchers then found that under the pulsed mild current that DBS creates, those in the study—all in early stages of the disorder—showed increases in glucose metabolism that mark heightened activity in known memory circuits. The effect lasted over the 13-month test period. Most patients with AD would normally see decreases in that length of time.

“Recent failures of the large trials of drugs that target beta-amyloid plaques, a prime AD suspect in the brain, have sharpened our need for alternative strategies,” says psychiatrist Paul Rosenberg, site director of the new work at Johns Hopkins. “Trying to enhance brain function by mechanical means is a whole new avenue to explore.”

Patients undergoing DBS carry a pacemaker-like stimulator implanted just under the skin. An electrode extends from it, painlessly, to the brain. The arrangement isn’t new: DBS is well-established for Parkinson’s disease. And it’s under study for depression and chronic pain.

In this newest work, some 40 Alzheimer’s patients will receive DBS over the next year or so at Hopkins and four other North American medical centers—all part of the ADvance Study co-led by Johns Hopkins psychiatrist Constantine Lyketsos and neurologist Andres Lozano at the University of Toronto. Only those impaired mildly enough to still be able to make informed decisions can participate.